Transmission

ABSTRACT

A transmission, having a first input shaft X 1 , a second input shaft X 2 , an output shaft Xs and an idle shaft X R , wherein two gears G 1 , G 2  are carried on a sleeve S G  fitted rotatably on said first input shaft X 1 , and one (G 1 ) of said gears of said sleeve S G  engages with a gear G 16  being fixedly carried on said counter shaft Xs, while the other gear G 2  engages with a gear G 7  being fixedly carried on said output shaft Xo, and further, a coupling C 1  is attached between said one (G 1 ) of said gears and the other gear G 2 , to fix selectively said gear G 1  or G 2  to said input shaft X 1 , is provided in the present invention.

FIELD OF THE INVENTION

This invention relates to a twin clutch type automotive transmission.

BACKGROUND OF THE INVENTION

Up to now, a twin-clutch type transmission (1) has been provided, asshown in FIG. 3, having a first input shaft X1 connecting to a firstclutch D1, a second input shaft X2, inserted in said first input shaftX1, connecting to a second clutch D2, an output shaft Xo, a countershaft Xs, and an idle shaft X_(R), wherein 4th and 6th speed drive gearsG18, G19 are rotatably carried on said first input shaft X1, the 2nddrive gear G20 is fixedly carried on said first input shaft X1, and acoupling C5 to fix selectively said rotatable gears G18, G19 to saidfirst input shaft X1 is attached between said two gears G18, G19, the1st, 3rd, and 5th drive gears G21, G22, G23 are fixedly carried on saidsecond input shaft X2, the 4th and 6th speed driven gears G24, G25engaging respectively with said rotatable two gears G18, G19 of saidfirst input shaft X1 are fixedly carried on said output shaft Xo, the1st and 5th speed driven gears G26, G27 engaging respectively with saidtwo fixed gears G21, G23 of said second input shaft X2 are rotatablycarried on said output shaft Xo, an output gear G12 connecting to adifferential gear(4) is fixedly carried on said output shaft Xo on theclutch-most side, and a coupling C6 to fix selectively two rotatablegears G26, G27 to said output shaft Xo is attached between said twogears, the 3rd speed driven gear G28 engaging with said gear G22 of saidsecond input shaft X2 and a gear G30 connecting to said gear G21 of saidsecond input shaft X2 through a gear G29 carried fixedly on said idleshaft X_(R,) are respectively rotatably carried on said counter shaftXs, and a gear G31 engaging with said gear G18 of said first input shaftis fixedly carried on said counter shaft Xs, and the 2nd speed drivengear G32 engaging with said gear G20 of said first input shaft X1 isrotatably carried on said counter shaft Xo, furthermore, couplings C7,C8 to fix selectively three rotatable gears G28, G30, G32 to saidcounter shaft Xs are respectively attached between said gears G28 andG30, and to said gear G32.

In above described transmission (1), said gear G32 and said coupling C8attached to said gear G32 are arranged in a side space SP of said outputgear G12 of said output shaft Xo.

In said conventional transmission (1), to attain 2nd speed or 3rd speedor reverse, the 4th drive gear G18 of said first input shaft X1 is usedas an idle gear, so that excessive load effects on said gear G18, andthe mechanical strength of the bearing part of said gear G18 isinsufficient, resulting in the degradation of the durability of saidtransmission (1).

Accordingly, to ensure the mechanical strength of the bearing part ofsaid gear G18, increasing the diameter of the bearing part of said gearG18 to increase volume of the bearing part of said gear G18, has beenconsidered, however, since the gear diameter of said gear G18 is settledby the gear ratio of the 4th drive gear G18 to the driven gear G24, in acase where the gear diameter of said gear G18 is settled to be large,the distance between said first input shaft X1 and said output Xo alsoincreases, resulting in an oversized transmission, which is troublesometo install in an automobile. Furthermore, in a case where the shaftlength of the bearing part of said gear G18 is enlarged to increase thevolume of the bearing part of said gear G18, the shaft direction size ofsaid transmission (1) is also enlarged, according to any enlargements ofshaft length, thus causing trouble. In the case of twin clutch typetransmission (1), particularly in the case of a front wheel drive systemwhere the engine is installed sideways, narrowing the transmissioninstallation space, the shaft length is difficult to accommodate in thespace available.

Further, since the 2nd speed gear G20 of said first input shaft X1 isfor a lower speed gear, the diameter of said gear is settled to besmall, and the diameter of said first input shaft X1 is settled to besmall, according to the diameter of said gear G20. Accordingly, thediameter of said second input shaft X2, inserted in said hollow,tube-like first input shaft X1, is necessary to be settled to besmaller, resulting in its mechanical strength being insufficient todegrade the durability of said transmission (1).

In this case, the diameter of said gear G20 is settled by the gear ratioof 2nd drive gear G20 to said driven gear G32, and in the case where thediameter of said gear G20 is enlarged, increasing the distance betweensaid first input shaft X and said counter shaft Xs, the result is anenlarged transmission size, which is troublesome to install in anautomobile, given the space provided therefor.

DISCLOSURE OF THE INVENTION

To solve above described problems in said conventional transmission, thepresent invention provide a transmission, having a first input shaft X1connecting to a first clutch D1, a second input shaft X2, inserted insaid first input shaft X1, connecting to a second clutch D2, an outputshaft Xo, a counter shaft Xs and an idle shaft X_(R), wherein a sleeveS_(G) on which two gears G1, G2 are carried is rotatably fitted on saidfirst input shaft X1, a gear G3 is rotatably carried on said first inputshaft, and a gear G4 is fixedly carried on said first input shaft X1,and further, a coupling C1 to fix selectively one (G1) of said rotatablegears G1, G2 of said sleeve S_(G) and said rotatable gear G3 of saidfirst input shaft X1 to said first input shaft is attached between saidrotatable gears G1 and G3, two gears G5, G6 are fixedly carried on saidsecond input shaft X2, two gears G7, G8 engaging with the otherrotatable gear G2 of said sleeve S_(G) and said rotatable gear G3 ofsaid first input shaft are respectively fixedly carried on said outputshaft Xo, two gears G9, G10 engaging respectively with said two fixedgears G5, G6 of said second input shaft X2 are rotatably carried on saidoutput shaft Xo, an output gear G12 connecting to a differencial gear(4) is fixedly carried on said output shaft Xo on the clutch—most side,and further, a coupling C2 to fix selectively said two rotatable gearsG9, G10 to said output shaft Xo is attached between said rotatable gearsG9 and G10, a gear G13 engaging with one (G6) of two fixed gears G5, G6of said second input shaft X2, and a gear G15 connecting to the otherfixed gear G5 of said second input shaft X2 through a gear G14 carriedfixedly or rotatably on said idle shaft X_(R), are rotatably carried onsaid counter shaft Xs, a gear G16 engaging with one (G1) of said twogears G1, G2 of said sleeve S_(G) rotatably fitted on said first inputshaft X1 is fixedly carried on said counter shaft Xs, a gear G17engaging with said fixed gear G4 of said first input shaft X1 isrotatably carried on said counter shaft, and two couplings C3, C4 to fixselectively said three rotatable gears G13, G15, G17 to said countershaft Xs are attached, and further, said gear G17 of said counter shaftXs engaging with said fixed gear G4 of said first input shaft X1 andsaid coupling C4 of said counter shaft Xs are arranged in a side spaceof said output gear G12 of said output shaft Xo.

Since said two gears G1, G2 are carried on said sleeve S_(G) fittedrotatably on said first input shaft X1, the shaft length of the bearingpart of said sleeve S_(G) on which said gears G1, G2 are carried can beenlarged to increase the bearing volume of said sleeve S_(G) on whichsaid gears are carried, hence, the durability of said transmission canbe improved.

Furthermore, in the case where the diameter of one (G1) of said gears issettled to be desirably-larger than the diameter of the other gear G2,the gear ratio can be adjusted without changing the distance betweensaid first input shaft X1 and said output shaft Xo and the distancebetween said first input shaft X1 and said counter shaft Xo, so that thediameter of each gear can be settled without the limitations of the gearratio.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a descriptive drawing that shows an embodiment of thisinvention.

FIG. 2 is a descriptive drawing that shows another embodiment of thisinvention.

FIG. 3 is a descriptive drawing that shows a prior art.

DESCRIPTION OF NOTATIONS

-   1 Transmission-   2 Engine-   3 Tire-   4 Differential gear-   X1 First input shaft-   X2 Second input shaft-   Xo Output shaft-   Xs Counter shaft-   X_(R) Idle shaft-   D1 First clutch-   D2 Second clutch-   G1–G17 Gears-   C1˜C4 Couplings-   S_(G), S1˜S4 Sleeves-   H1–H7 Hubs

PREFERRED EMBODIMENT OF THE INVENTION

The present invention is described herein referring to an embodimentshown in FIG. 1. In said embodiment, a twin-clutch type six-speedautomotive transmission (1) as shown in FIG. 1 is illustrated.

As shown in FIG. 1, said six-speed transmission (1) has a hollow,tube-like first input shaft X1, a second input shaft X2 inserted in saidfirst input shaft X1, an output shaft Xo, a counter shaft Xs, and anidle shaft X_(R), and a first clutch D1 and a second clutch D2 areconnected respectively to said first input shaft X1 and said secondinput shaft X2 to transmit power from an engine (2) to said shafts X1,X2.

Two drive gears G1, G2 are carried on a sleeve S_(G) and said sleeveS_(G) is fitted rotatably on said first input shaft X1, a drive gear G3for the 6th speed is rotatably carried on said first input shaft X1, adrive gear G4 for the 2^(nd)-speed is fixedly carried on said firstinput shaft X1, said gears G1, G3 have hubs H1, H2 respectively, and acoupling C1 having a sleeve S1 is attached between said gears G1 and G3,and the diameter of one. (G1) of said gears is settled to be larger thanthe diameter of the other gear G2. Drive gears, G5, for the 1st speedand G6 for the 3^(rd)-speed or 5^(th)-speed are fixedly carried on saidsecond input shaft X2 respectively.

Driven gears G7, G8, for the 4^(th)-speed and 6^(th)-speed engagingrespectively with the other gear G2 of said sleeve S_(G) fittedrotatably on said first input shaft X1 and the 6^(th) speed drive gearsG3, are fixedly carried on said output shaft Xo, driven gears G9, G10for the 1^(st)-speed and 5^(th)-speed engaging respectively with the1^(st)-speed, and the 3rd speed or 5^(th)-speed gears G4, G6 of saidsecond input shaft X2 are rotatably carried on said output shaft Xo, anoutput gear G12 engaging with a gear G11 of a differential gear (4) totransmit power to the tire (3) is fixedly carried on said output shaftXo, furthermore, said gears G9, G10 have hubs H3, H4 respectively and acoupling C2 having a sleeve S2 is attached between said gears G9 andG10. Further, said output gear G12 is arranged on the most-clutch side.

A driven gear G13 for the 3^(rd)-speed engaging with said gear G6 ofsaid second input shaft X2, and a driven gear G15 for reverse connectingto said gear G5 of said second input shaft X2 through a gear G14 fixedlycarried on said idle shaft X_(R), are rotatably carried on said countershaft Xs, a gear G16 engaging with said one (G1) of said gears of saidsleeve S_(G) fitted rotatably on said first input shaft X1 is fixedlycarried on said counter shaft Xs, a driven gear G17 for the 2^(nd)-speedengaging with said gear G4 of said first input shaft X1 is rotatablycarried on said counter shaft Xs, said gears G13, G15 have hubs H5, H6respectively, a coupling C3 having a sleeve S3 is attached between saidgears G13 and G15, said gear G17 has a hub H7, and a coupling C4 havinga sleeve S4 is attached to said gear G17.

Further, said gear G17 and said coupling C4 attached to said gear G17are arranged in the side space SP of said output gear G12 of said outputshaft Xo.

In this invention, said gear G14 of said idle shaft X_(R), may berotatably carried on said idle shaft X_(R).

As described above, by carrying said two gears G1, G2 on said sleeveS_(G) fitted rotatably on said input shaft X1, the shaft length of thebearing part of said sleeve S_(G) carrying said gears G1, G2 can beenlarged to increase the bearing volume of said sleeve S_(G) carryingsaid gears G1, G2, so that the durability of said transmission (1) canbe improved.

Furthermore, in a case where the diameter of one(G1) of gears isadjusted to be larger than the diameter of the other gear G2, the gearratio can also be adjusted without changing the distance between saidfirst input shaft X1 and said output shaft Xo and the distance betweensaid first input shaft X1 and said counter shaft Xs, so that thediameter of each gear can be settled without the limitations of the gearratio.

As described above, since the diameter of each gear can be settledwithout the limitations of the gear ratio, the diameter of the 2nd speeddrive gear G4 can be settled to be large, although said 2nd speed drivegear G4 is for a low speed, so that the diameter of said first inputshaft X1 can also be settled to be large, according to the diameter ofsaid gear G4, and accordingly, the diameter of said second input shaftX2, inserted in said hollow first input shaft X1, can be settled to beeven larger, and the durability of said transmission (1) can beimproved, ensuring the mechanical strength of said second input shaftX2.

Furthermore, since the gear ratio can be adjusted without changing thedistance between shafts, said gear G6 of said second input shaft X2 canbe used as the drive gear both for the 3rd speed and 5th speed to savespace along the shaft equivalent to that of a pair of gears, so that thesize of said transmission (1) along said shaft does not increase, evenif the shaft length of the bearing part of said sleeve S_(G) is builtlarger.

The action of said transmission (1) is illustrated bellow.

[1^(st) Speed]

Said sleeve S2 is slid toward the 1^(st) speed driven gear G9 to connectsaid coupling C2 and said hub H3 of said gear G9, and the rotation ofsaid second input shaft X2 is transmitted to said output shaft Xothrough the 1^(st) speed driven gear G9 from the 1^(st) speed drive gearG5, and the rotation of said output shaft Xo is transmitted to said gearG11 of said differential gear (4) through said output gear G12, toattain 1^(st) speed.

[2^(nd) Speed]

Said sleeve S4 is slid toward the 2^(nd) speed driven gear G17 toconnect said coupling C4 and said hub H7 of said gear G17, and therotation of said first input shaft X1 is transmitted to said countershaft Xs through the 2^(nd) speed driven gear G17 from the 2^(nd) speeddrive gear G4, and further transmitted to said sleeve S_(G) through one(G1) of said gears of said sleeve S_(G) of said first input shaft X1from said gear G16 of said counter shaft Xs, and then transmitted tosaid output shaft Xo through said gear G7 of said output shaft Xo fromthe other gear G2 of said sleeve S_(G), and the rotation of said outputshaft Xo is transmitted to said gear G11 of said differential gear (4)through said output gear G12, to attain 2^(nd) speed.

[3^(rd) Speed]

Said sleeve S3 is slid toward the 3^(rd) speed driven gear G13 toconnect said coupling C3 and said hub H5 of said gear G13, and therotation of said second input shaft X2 is transmitted to said countershaft Xs through the 3^(rd) speed driven gear G13 from the 3^(rd) or the5th speed drive gear G6, and further transmitted to said sleeve S_(G)through one (G1) of gears of said sleeves S_(G) of said first inputshaft X1 from said gear G16 of said counter shaft Xs, and furthertransmitted to said output shaft Xo through said gear G7 of said out putshaft Xo from the other gear G2 of said sleeve S_(G), and the rotationof said output shaft Xo is transmitted to said gear G11 of saiddifferential gear (4) through said output gear G12, to attain 3^(rd)speed.

[4^(th) Speed]

Said sleeve S1 is slid toward one (G1) of said gears of said sleeveS_(G) of said first input shaft X1 to connect said coupling C1 and saidhub H1 of said gear G1, and the rotation of said first input shaft X1 istransmitted to said sleeve S_(G) through one (G1) of said gears of saidsleeve S_(G) of said first input shaft X1, and further transmitted tosaid output shaft Xo through said gear G7 of said output shaft Xo fromthe other gear G2 of said sleeve S_(G), and the rotation of said outputshaft Xo is transmitted to said gear G11 of said differential gear (4)through said output gear G12, to attain 4^(th) speed.

[5^(th) Speed]

Said sleeve S2 is slid toward 5-speed driven gear G10 to connect saidcoupling C2 and said hub H4 of said gear G10, and the rotation of saidsecond input shaft X2 is transmitted to said output shaft Xo through the5^(th) speed driven gear G10 from the 3rd or the 5^(th) speed drive gearG6, and the rotation of said output shaft Xo is transmitted to said gearG11 of said differential gear (4) through said output gear G12, toattain 5^(th) speed.

[6^(th) Speed]

Said sleeve S1 is slid toward the 6^(th) speed drive gear G3 to connectsaid coupling C1 and hub H2 of said gear G3, and the rotation of saidfirst input shaft X1 is transmitted to said output shaft Xo through the6^(th) speed driven gear G8 from the 6^(th) speed drive gear G3, and therotation of said output shaft Xo is transmitted to said gear G11 of saiddifferential gear (4) through said output gear G12, to attain 6^(th)speed.

[Reverse]

Said sleeve G3 is slid toward said reverse driven gear G15 to connectsaid coupling C3 and said hub H6 of said gear G15, and the rotation ofsaid second input shaft X2 is transmitted to said counter shaft Xsthrough said reverse driven gear G15 being reversed by said gear G14 ofsaid idle shaft X_(R) from said gear G5 of said second input shaft X2,and then transmitted to said sleeve S_(G) through one (G1) of said gearsof said sleeves S_(G) of said first input shaft X1 from said gear G16 ofsaid counter shaft Xs, and then further transmitted to said output shaftXo through said gear G7 of said output shaft Xo from the other gear G2of said sleeve S_(G), and the rotation of said output shaft Xo istransmitted to said gear G11 of said differential gear (4) through saidoutput gear G12, to attain reverse.

In addition to this embodiment, as shown in FIG. 2, a hub H1 may beattached to the other gear G2 of said sleeve S_(G) of said first inputshaft X1 and a coupling C1 having a sleeve S1 may be attached betweensaid gears G2 and G3. In this case, to attain 4th speed, said sleeve S1is slid toward the other gear G2 of said sleeve S_(G) of said firstinput shaft X1 to connect said coupling C1 and said hub H1 of said gearG2, and the rotation of said first input shaft X1 is transmitted to saidoutput shaft Xo through said gear G7 of said output shaft Xo from theother gear G2 of said sleeve S_(G) of said first input shaft X1, andthen the rotation of said output shaft Xo is transmitted to said gearG11 of said differential gear (4) through said output gear G12,attaining 4^(th) speed.

INDUSTRIAL UTILITY

In the present invention, the mechanical strength of the gear and thebearing volume can be ensured without enlarging the transmission,improving the durability thereof.

1. A transmission having a first input shaft connecting to a firstclutch, a second input shaft, inserted in said first input shaft,connecting to a second clutch, an output shaft, a counter shaft and anidle shaft, wherein a sleeve on which two gears are carried is rotatablyfitted on said first input shaft, a gear is rotatably carried on saidfirst input shaft, and a gear is fixedly carried on said first inputshaft, and further, a coupling to fix selectively one of said rotatablegears of said sleeve and said rotatable gear of said first input shaftto said first input shaft is attached between said rotatable gears, twogears are fixedly carried on said second input shaft, two gears engagingwith the other rotatable gear of said sleeve and said rotatable gear ofsaid first input shaft are respectively fixedly carried on said outputshaft, two gears respectively engaging with said two fixed gears of saidsecond input shaft are rotatably carried on said output shaft, an outputgear connecting to a differential gear is fixedly carried on said outputshaft on the most-clutch side, and further, a coupling to fixselectively said two rotatable gears to said output shaft is attachedbetween said rotatable gears, a gear engaging with one of two fixedgears of said second input shaft, and a gear connecting to the otherfixed gear of said second input shaft through a gear carried fixedly orrotatably on said idle shaft, are rotatably carried on said countershaft, a gear engaging with one of said two gears of said sleeverotatably fitted on said first input shaft is fixedly carried on saidcounter shaft, a gear engaging with said fixed gear of said first inputshaft is rotatably carried on said counter shaft, and two couplings tofix selectively said three rotatable gears to said counter shaft areattached to said rotatable gears, and further, said gear of said countershaft engaging with said fixed gear of said first input shaft and saidcoupling of said counter shaft, are arranged in a side space of saidoutput gear of said output shaft.